From 92cc282d121c2f5b842a661dae9cf4cb199c4d46 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sun, 9 Jun 2024 22:03:12 -0400 Subject: kernel/amd64: pmap: Add initial pmap code Signed-off-by: Ian Moffett --- sys/include/vm/pmap.h | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 sys/include/vm/pmap.h (limited to 'sys/include/vm/pmap.h') diff --git a/sys/include/vm/pmap.h b/sys/include/vm/pmap.h new file mode 100644 index 0000000..ec669a8 --- /dev/null +++ b/sys/include/vm/pmap.h @@ -0,0 +1,64 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _VM_PMAP_H_ +#define _VM_PMAP_H_ + +#include +#include + +/* Protection flags for mappings */ +#define PROT_READ 0x00000000UL +#define PROT_WRITE BIT(0) /* Writable */ +#define PROT_EXEC BIT(1) /* Executable */ +#define PROT_USER BIT(2) /* User accessible */ + +typedef uint32_t vm_prot_t; + +/* + * Fetch the current address space. + */ +struct vas pmap_read_vas(void); + +/* + * Switch the virtual address space. + */ +void pmap_switch_vas(struct vas vas); + +/* + * Create a virtual memory mapping of a single page. + */ +int pmap_map(struct vas vas, vaddr_t va, paddr_t pa, vm_prot_t prot); + +/* + * Unmap a virtual memory mapping of a single page. + */ +int pmap_unmap(struct vas vas, vaddr_t va); + +#endif /* !_VM_PMAP_H_ */ -- cgit v1.2.3 From 347a1a0eeb5aa84e287e443a468a47a0fafd153f Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sun, 23 Jun 2024 19:01:29 -0400 Subject: kernel/amd64: pmap: Add function to create new VAS Signed-off-by: Ian Moffett --- sys/arch/amd64/amd64/pmap.c | 33 +++++++++++++++++++++++++++++++++ sys/include/vm/pmap.h | 5 +++++ 2 files changed, 38 insertions(+) (limited to 'sys/include/vm/pmap.h') diff --git a/sys/arch/amd64/amd64/pmap.c b/sys/arch/amd64/amd64/pmap.c index 6047699..108cd91 100644 --- a/sys/arch/amd64/amd64/pmap.c +++ b/sys/arch/amd64/amd64/pmap.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -191,6 +192,38 @@ pmap_update_tbl(struct vas vas, vaddr_t va, uint64_t val) return 0; } +int +pmap_new_vas(struct vas *res) +{ + const struct vas *kvas = &g_kvas; + struct vas new_vas; + uint64_t *src, *dest; + + new_vas.cr3_flags = kvas->cr3_flags; + new_vas.top_level = vm_alloc_frame(1); + if (new_vas.top_level == 0) + return -ENOMEM; + + src = PHYS_TO_VIRT(kvas->top_level); + dest = PHYS_TO_VIRT(new_vas.top_level); + + /* + * Keep the higher half but zero out the lower + * half for user programs. + */ + for (int i = 0; i < 512; ++i) { + if (i < 256) { + dest[i] = 0; + continue; + } + + dest[i] = src[i]; + } + + *res = new_vas; + return 0; +} + struct vas pmap_read_vas(void) { diff --git a/sys/include/vm/pmap.h b/sys/include/vm/pmap.h index ec669a8..dccfe0d 100644 --- a/sys/include/vm/pmap.h +++ b/sys/include/vm/pmap.h @@ -51,6 +51,11 @@ struct vas pmap_read_vas(void); */ void pmap_switch_vas(struct vas vas); +/* + * Create a new virtual address space. + */ +int pmap_new_vas(struct vas *res); + /* * Create a virtual memory mapping of a single page. */ -- cgit v1.2.3